Largest solar storm in 7 years could disrupt GPS signals, power grid

By Kevin McCaney

Jan 23, 2012

The impact of the largest solar storm in almost seven years is expected to hit Earth Jan. 24 and could cause slight disruptions in Global Positioning System signals and the electric grid. And at high latitudes, it could make for some brilliant Northern Lights.

Charged particles from the sun are expected to peak about 9 a.m. Eastern Standard Time, according to The National Weather Service’s Space Weather Prediction Center.

The latest burst follows one over the weekend that resulted in Northern Lights being seen in Canada, Northern England and other places. In the United States Tuesday night, it's possible the aurora could be seen as far south as the latitudes spanning New England to Oregon.

The Space Weather Prediction Center has issued a Geomagnetic Storm Watch for the storm, the biggest since May 2005, saying G2 level storming is likely and G3 level storming is possible.

On the National Oceanic and Atmospheric Administration’s five-level Space Weather Scale for Geomagnetic Storms, G2 is considered moderate, with possible disruption to power systems and high-frequency radio transmissions at higher latitudes and a slight effect on the orbits of spacecraft, such as satellites.

G3 is rated strong, and could have a greater effect on voltage flows and satellite operations. Threats of serious problems with power grids and satellites, however, would occur at levels G4 and G5, which are not expected.

Although it won’t be strong enough to drive anybody into the bunkers, it nevertheless could cause some trouble. Doug Biesecker, a physicist at the Space Weather Prediction Center, told the Washington Post there could be problems with satellite operations and high-frequency radio transmissions in the polar regions, which could affect air traffic controls for flights between North America and Europe or Asia.

Solar cycles last about 11 years, with ebbs and flows in the amount of x-ray radiation released from sunspots. The current cycle is expected to peak in May 2013, according to a NOAA panel, sponsored by NASA, that came up with a prediction for the cycle in 2009.

And although the current cycle is considered to be below average in sunspot activity, it doesn’t mean there is no danger. In announcing that 2009 prediction, Biesecker pointed out that the geomagnetic storm of 1859, which electrified transmission cables, sets fires in telegraph offices and produced Northern Lights bright enough to read by, happened during a solar cycle about the same size as the current one.

A National Academy of Sciences report has said that a similar storm today could cause up to $2 trillion in damages to the current infrastructure.

One of the most well-known solar storms occurred in March 1989, when the magnetic disturbance from a massive storm created electrical current in the ground under North America, and took out the entire power grid for Quebec for 12 hours.

In December 2006, a solar flare disrupted GPS signals across a wide swath of the planet.

The Space Weather Prediction Center said it will be providing updates on the current storm on its Facebook page.